University of Nebraska - Lincoln
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Faculty Papers and Publications in Animal Science
Animal Science Department
2013
Impacts of a Limit-Feeding Procedure on Variation
and Accuracy of Cattle Weights
A. K. Watson
University of Nebraska-Lincoln, [email protected]
B. L. Nuttelman
University of Nebraska-Lincoln
T. J. Klopfenstein
University of Nebraska-Lincoln, [email protected]
L. W. Lomas
Kansas State University Southeast Agricultural Research Center
G. E. Erickson
University of Nebraska-Lincoln, [email protected]
Follow this and additional works at: http://digitalcommons.unl.edu/animalscifacpub
Watson, A. K.; Nuttelman, B. L.; Klopfenstein, T. J.; Lomas, L. W.; and Erickson, G. E., "Impacts of a Limit-Feeding Procedure on
Variation and Accuracy of Cattle Weights" (2013). Faculty Papers and Publications in Animal Science. Paper 790.
http://digitalcommons.unl.edu/animalscifacpub/790
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Impacts of a limit-feeding procedure on variation and accuracy of cattle weights1
A. K. Watson,* B. L. Nuttelman,* T. J. Klopfenstein,*,2 L. W. Lomas,† and G. E. Erickson*
*Department of Animal Science, University of Nebraska–Lincoln, Lincoln 68583-0908;
and †Kansas State University Southeast Agricultural Research Center, Parsons 67357
ABSTRACT: Cattle weights can be highly variable and
are influenced by many factors, including time of weighing, ambient temperature, feed intake, and cattle handling.
A protocol of limit feeding has been in use since the 1980s
that was designed to reduce variation in gut fill due to differences in intakes. Cattle are penned and fed a 50% hay,
50% wet corn gluten feed or grain diet (DM basis) at an
estimated 2% of BW for at least 5 d, after which weights
are taken on 2 consecutive d and averaged for a limit-fed
BW (LFW). For this analysis, full-fed weights (FFW)
also were taken before the limit-feeding period while cattle had ad libitum intakes. Data from 18 experiments were
used to analyze differences within 2-d LFW and between
LFW and FFW. For 10 of the 18 experiments, FFW also
were measured on 2 consecutive d. Cattle included in this
summary were grazing cornstalks, smooth bromegrass
pasture, Bermuda grass pasture, fescue pasture, native
range, or in a dry lot on a 70% forage diet. The largest
differences between FFW and LFW for individual cattle
were -39 to +44 kg over all 18 experiments. Differences
between 2 consecutive d of LFW were -23 to +24 kg for
all 18 experiments. Differences between 2 d of FFW were
-14 to +34 kg in the 10 experiments measuring FFW on 2
consecutive d. There was not a clear relationship between
FFW and LFW; each weighing scenario had unique environmental conditions that led to different relationships.
Differences in both beginning and ending BW were compounded when calculating ADG. Average daily gain was
calculated for 15 of the experiments on the basis of either
LFW or FFW. Differences between LFW and FFW ADG
were -0.29 to +0.31 kg/d. The maximum ADG based on
FFW was 1.62 kg/d. This large ADG, on a forage based
diet, was likely due to changes in gut fill rather than tissue
gain. These data suggest that handling cattle in a similar
manner when weighing is more important than limiting
intakes to decrease variance between weights. However,
limiting intake before collection of beginning and ending BW better estimates empty body weight of cattle,
allowing for a more accurate determination of actual
body tissue weight gain. Measuring weights accurately
becomes especially crucial when evaluating multiple
components within a system (e.g., cornstalks to pasture
to feedlot). Feeding a standard diet between these components of the system minimizes differences in gut fill due to
treatment and allows for a more accurate determination of
each component’s contribution to the total system.
Key words: cattle weights, gut fill, limit feeding, multiple weights, weighing variation
© 2013 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2013.91:5507–5517
doi:10.2527/jas2013-6349
INTRODUCTION
Since the 1920s, researchers have recognized the
importance of accurate cattle weights and have debated the best method of obtaining them. There are 3
main sources of variation in cattle weights on different days: variation due to differences between animals,
changes in environmental conditions, and residual or
1A contribution of the University of Nebraska Agricultural Research
Division, supported in part by funds provided through the Hatch Act.
2Corresponding author: [email protected]
Received February 8, 2013.
Accepted September 3, 2013.
technique error (Baker and Guilbert, 1942; Patterson,
1947). Differences between animals can be minimized
by using similar age, breed, and size of animals within experiments. Using multiple-day weights can lead
to greater precision in weighing cattle (Stock et al.,
1983). Changes in environmental conditions include
changes in time of weighing, temperature, amount and
type of feed consumed, and how the cattle are handled.
Differences due to time of weighing and how the cattle
are handled can be minimized. Differences in amount
of feed consumed, and thus the weight of digestive tract
contents, may be the largest source of error in weighing
cattle, especially for cattle on bulky, forage-based diets
5507
5508
Watson et al.
(Koch et al., 1958). Obtaining accurate weights enhances
researchers’ ability to calculate statistical differences and
to have repeatability of results (Whiteman et al., 1954;
Stock et al., 1983).
The most accurate way of measuring actual tissue
weights is to slaughter the cattle and record carcassbased weights (Meyer et al., 1960). Although accurate,
this method is costly and impractical for large numbers
of cattle on growing studies. Some researchers have
implemented a protocol for limit-feeding cattle and then
weighing early in the morning on 2 or more consecutive
days. This protocol attempts to minimize variability in
cattle weights due to rumen fill from changes in feed
intake and time of day of weighing. This protocol has
been implemented for many years, but differences in
BW due to a limit-feeding period have never been verified. Therefore, the objective of this study was to document variation within and differences and relationships
between limit-fed and full-fed weights.
MATERIALS AND METHODS
All cattle were managed in accordance with the
protocols approved by the Animal Care and Use
Committees at the University of Nebraska and Kansas
State University.
Cattle weight data were collected from 8 experiments conducted at the University of Nebraska
Agricultural Research and Development Center near
Mead, NE, and 10 experiments conducted at the Kansas
State University Southeast Agricultural Research Center
near Parsons, KS. The 18 forage-based growing experi-
ments are summarized in Table 1. At both research stations, cattle on trial had ad libitum intakes and were
weighed directly off trial for a full-fed weight (FFW).
These same groups of cattle were then fed at an estimated 2% of BW for at least 5 d, after which limit-fed
weights were taken on 2 consecutive d and averaged for
an ending limit-fed BW (LFW). In 15 of these experiments, initial LFW were also measured, and ADG was
calculated for cattle on the basis of either FFW or LFW.
Two of the experiments had initial FFW.
Animal Management
For all research experiments conducted at the
University of Nebraska, a standard protocol is followed
to obtain beginning and ending BW on all animals. Cattle
are penned for at least 5 d while being limit fed at an
estimated 2% of BW a diet consisting of 50% wet corn
gluten feed (Sweet Bran, Cargill Inc., Blair, NE) and 50%
hay (DM basis). Cattle are then weighed on 2 or 3 consecutive d to obtain an average beginning BW. For growing experiments, cattle are again limit fed at 2% of BW
for at least 5 d at the conclusion of the experiment and
then weighed on 2 or 3 consecutive d to obtain an average ending BW. Cattle are group fed during the 5 d of
limit feeding at an estimated 2% of BW. Group feeding
has the potential to bias weights by allowing dominant
animals to consume more than 2% of BW while limiting
shy feeders to less than 2% of BW. To combat this, cattle
are allowed a minimum of 0.41 m (16 inches) of bunk
space per animal during limit feeding. Feed is typically
Table 1. Description of cattle on each experiment
Research Station1 Exp. No. of cattle Beginning LFW2
UNL
1
45
325
UNL
2
75
308
UNL
3
32
325
UNL
4
116
—
UNL
5
257
—
UNL
6
231
285
UNL
7
258
—
UNL
8
509
304
KSU
9
36
199
KSU
10
36
220
KSU
11
36
226
KSU
12
36
205
KSU
13
36
212
KSU
14
36
204
KSU
15
40
340
KSU
16
40
334
KSU
17
40
369
KSU
18
72
250
Beginning FFW2 End LFW2 End FFW2
—
462
475
—
475
477
—
402
399
—
349
345
—
285
283
283
375
372
—
304
290
290
328
352
—
378
377
—
364
372
—
370
384
—
377
388
—
400
416
—
389
406
—
440
450
—
423
434
—
466
469
—
443
456
Year
2009
2011
2011
2011
2011
2011
2011
2011
2005
2006
2007
2008
2009
2010
2006
2007
2008
2010
Diet
Duration, d
Smooth bromegrass pasture
168
Smooth bromegrass pasture
168
Native range
121
Native range
62
Smooth bromegrass pasture
20
Native range
128
Cornstalk residue
90
Forage based growing study
58
Smooth bromegrass pasture
196
Smooth bromegrass pasture
161
Smooth bromegrass pasture
182
Smooth bromegrass pasture
196
Smooth bromegrass pasture
221
Smooth bromegrass pasture
224
Bermuda grass pasture
89
Bermuda grass pasture
105
Bermuda grass pasture
105
Fescue pasture
224
1UNL = University of Nebraska–Lincoln; KSU = Kansas State University.2Full-fed weights (FFW) were measured while cattle had ad libitum intakes, limitfed weights (LFW) were measured after a 5-d period of restricting intakes to 2% of BW.
Variation in cattle weights
cleaned up by noon; cattle are then weighed at 0700 h the
following morning, after which they are fed for the day.
For finishing experiments, beginning BW is obtained the same way as growing experiments, but ending BW is determined by carcass weight at the packing
plant (no gut fill variation) using a constant 63% dress
to adjust HCW to LFW. Precautions are taken to avoid
excessive trim on carcasses, which would affect HCW.
For the 10 experiments done at Kansas State
University and included in this summary, cattle were
weighed on 2 consecutive d while still on trial to obtain a full ending BW. These cattle were then limit fed
for at least 6 d and weighed on 2 consecutive d for a
limit-fed ending BW. Limit feeding consisted of penning
the cattle and feeding a 50% prairie hay and 50% grain
sorghum or shelled corn diet at an estimated 2% of BW.
All weights, both limit fed and full, were an average
of 2 consecutive d of weights. Cattle were penned near
scales for the limit-feeding period. Therefore, they traveled a shorter distance to the scales for LFW than FFW.
However, they were not moved long distances for the
FFW. All weights were taken at approximately 0800 h.
Cattle weights can be influenced by cattle handling
both before and during the weighing procedure. The following is a detailed description of how the cattle were
handled leading up to both FFW and LFW for the 18
experiments included in this study (Table 1).
Experiment 1
In October of 2009 single-day full weights were
taken on 45 steer calves that had grazed smooth bromegrass pasture for 168 d (Watson et al., 2012). Cattle were
pulled from pasture at 0600 h, moved approximately 0.8
km to the handling facility, and penned for 1 h while
being weighed (FFW). They were then moved less than
0.4 km to feedlot pens to be limit fed for 7 d, after which
weights were taken on 2 consecutive d. The LFW were
taken at 0630 h, and cattle were back in pens by 0730 h.
Experiment 2
In a similar experiment, 75 steer calves were
weighed in October of 2011 after grazing smooth bromegrass pasture for 168 d (Pruitt et al., 2012). Cattle were
pulled from pasture at 0600 h, moved approximately 0.8
km to the handling facility, and penned for 2 h while being weighed. They were then moved less than 0.4 km to
feedlot pens to be limit fed for 6 d, after which weights
were taken on 2 consecutive d. The LFW were taken at
0630 h, and cattle were back in pens by 0830 h.
5509
Experiment 3
In May of 2011, 32 steer calves were limit fed for
5 d and then weighed on 2 consecutive d to obtain a
beginning LFW. They then grazed native range in the
Sandhills near Rose, NE, for 121 d. After grazing native range, cattle were moved approximately 0.8 km
to a portable chute and loaded on semitrucks by 1100
h. They were then shipped approximately 322 km to
Mead, NE, and unloaded, and a single-day FFW was
taken between 1630 and 1800 h. Cattle were then limit
fed for 7 d in pens less than 0.4 km from the handling
facility, after which LFW were taken on 2 consecutive
d. The LFW were taken between 0730 and 0930 h.
Experiment 4
In June of 2011, 116 steer calves were weighed
after mob grazing native range in the Sandhills near
Rose, NE, for 62 d. Cattle were moved approximately
0.8 km to a portable chute and loaded on semitrucks
by 1000 h. They were then shipped approximately
322 km to Mead, NE, and unloaded and a single-day
FFW was taken between 1430 and 1530 h. Cattle were
then limit fed for 7 d in pens less than 0.4 km from
the handling facility, after which LFW were taken on
2 consecutive d.
Experiments 5 and 6
In May of 2011, 257 heifer calves were weighed
after grazing smooth bromegrass pasture for 20 d (Exp.
5; Gillespie et al., 2012). For FFW, cattle were pulled
from pasture at 0700 h, moved 0.8 km to the handling
facility, and weighed by 1030 h. Cattle were then held
in 1 pen, 0.4 km from the handling facility, to be limit
fed for 7 d. Limit-fed weights were taken at 0800 h,
and cattle were back in the pen by 1100 h. On the first
day of LFW, heifers were also branded while in the
chute. Out of this pool of heifers, 231 then went to the
Sandhills near Rose, NE, to graze native range until
September (Exp. 6; Gillespie et al., 2012). After 128 d
of grazing, the heifers were moved approximately 0.8
km to a portable chute, loaded at 1100 h, and shipped
approximately 322 km to Mead, NE. A FFW was taken
between 1630 and 1800 h, after which the calves were
penned 0.4 km from the handling facility and limit fed
for 6 d. Limit-fed weights were taken on 2 consecutive
d, with cattle pulled from pens at 0700 h, weighed, and
returned to pens by 0930 h. For this group of heifers
ADG was then calculated for the 128 d of Sandhills
grazing on the basis of FFW beginning and ending
weights and LFW beginning and ending weights.
5510
Watson et al.
Experiment 7
In February 2011, 258 steer calves were weighed
after grazing cornstalks for approximately 90 d. Cattle
were pulled from the cornstalk field at 0700 h and moved
approximately 1.6 km on foot to the handling facility,
and FFW were taken between 0800 and 1030 h. They
were then penned 0.4 km from the handling facility to
be limit fed for 6 d. For LFW, cattle were weighed at
0700 h and returned to pens by 0900 h.
Experiment 8
In April 2011, 509 steer calves were weighed after
a growing experiment with diets consisting of choice
between 60% grass hay with 40% alfalfa mix and 70%
straw/cornstalk with 30% modified distillers grains plus
solubles mix (Weber et al., 2012). These cattle were
penned less than 0.4 km from the handling facility and
were limit fed for 5 d in the same pens they were in for
the growing study. For both FFW and LFW, cattle were
pulled from pens at 0730 h, weighed, and returned to their
pens by 1000 h. Both FFW and LFW weights were used
to calculate ADG for 258 of these steers. Ending FFW
and LFW on Exp. 7 served as initial FFW and LFW for
258 steers on Exp. 8.
Experiments 9 to 14
In April 2005, 36 steer calves were weighed on 2 consecutive d after being limit fed for 7 d (Exp. 9; Lomas and
Moyer, 2009). Calves then grazed smooth bromegrass
pastures for 196 d, after which FFW were taken on 2 consecutive d. Cattle were then penned and limit fed for 7 d,
and LFW were taken on 2 consecutive d. This weighing
procedure was repeated in 2006, 2007, 2008, 2009, and
2010 on 36 steer calves grazing smooth bromegrass pastures (Exp. 10, 11, 12, 13, and 14, respectively; Lomas
and Moyer, 2009, 2011a).
Experiments 15 to 17
In 2006, 2007, and 2008, 40 steer calves were
weighed on 2 consecutive d after being limit fed for 7 d
(Exp. 15, 16, and 17, respectively; Lomas and Moyer,
2009). Calves then grazed Bermuda grass pastures for an
average of 100 d, after which FFW were taken on 2 consecutive d. Cattle were then penned and limit fed for 6 or
7 d, and LFW were taken on 2 consecutive d.
Experiment 18
In March 2010, 72 steer calves were weighed on 2
consecutive d after being limit fed for 7 d (Lomas and
Moyer, 2011b). Calves then grazed fescue pastures for
Figure 1. Relationship between weights taken on the same group of
cattle using 2 different weighing procedures. Each point represents 1 animal
on 1 of the 18 experiments. Limit-fed weights (LFW) are an average of 2
consecutive d and were taken after a limit-feeding period. Full-fed weights
(FFW) are an average of 2 consecutive d in 10 experiments and a 1-d weight
in 8 experiments. Points below the isopleth represent animals with FFW
greater than LFW. Points above the isopleth represent animals with FFW less
than LFW. y = 0.93x + 19.84; r2 = 0.96.
224 d, after which FFW were taken on 2 consecutive d.
Cattle were then penned and limit fed for 7 d, and LFW
were taken on 2 consecutive d.
Data Analysis
Data were analyzed using the REG and GLIMMIX
procedures of SAS (SAS Inst. Inc., Cary, NC). For each
group of cattle, data were plotted with each animal’s
FFW as the independent variable on the x axis and LFW
as the dependent variable on the y axis. Figure 1 contains all of the data from each of the 18 experiments as
an example of how the data were plotted. Table 2 then
shows data from each of the experiments plotted and analyzed separately. Relationships between FFW and LFW
were examined by plotting a linear trend line. Standard
errors of the slope and intercept of the lines are reported.
Differences between FFW and LFW for each animal
were calculated, and an average difference and range of
differences are reported for each experiment.
The LFW data for all 18 groups of cattle were plotted with d 1 LFW on the x axis and d 2 LFW on the y
axis (Figure 2; Table 3). The 10 experiments conducted
at Kansas State University had FFW and LFW taken on
2 consecutive d. For these experiments, data were plotted
with each animal’s d 1 FFW on the x axis and d 2 FFW
on the y axis (Fig. 3 and Table 4).For the 10 experiments
conducted at Kansas State University equal slopes analysis
was performed to determine if the slope of the line for FFW
is different from the LFW slope (Table 2). Differences were
considered significant with a P-value ≤ 0.10.
In 15 of the experiments, beginning weights were
taken and ADG was calculated. For 2 of these experiments (Exp. 6 and 8) FFW ADG was calculated using
FFW for both beginning and ending weights, and LFW
5511
Variation in cattle weights
Table 2. Relationships between full-fed weights (FFW)
and limit-fed weights (LFW) at the conclusion of 18
experiments1
Exp.
1
r2
0.946
2
0.894
3
0.803
4
0.906
5
0.977
6
0.943
7
0.751
8
0.859
9
0.951
10
0.963
11
0.967
12
0.954
13
0.980
14
0.966
15
0.883
16
0.941
17
0.912
18
0.954
Equation
(SEs2) (SEI3)
1.03x − 30.68
(0.04) (18.79)
0.92x + 34.23
(0.03) (15.11)
0.95x + 21.64
(0.09) (34.49)
0.95x + 19.95
(0.03) (9.93)
1.01x − 4.38
(0.01) (2.77)
1.01x − 0.86
(0.02) (6.14)
0.88x + 46.82
(0.03) (9.26)
0.94x + 6.82
(0.02) (5.96)
1.05x − 17.3
(0.04) (15.43)
1.00x − 9.0
(0.03) (12.63)
1.03x − 25.1
(0.03) (12.64)
0.97x + 0.2
(0.04) (14.17)
1.02x − 27.4
(0.02) (10.45)
1.02x − 24.7
(0.03) (13.32)
1.04x − 31.3
(0.06) (27.67)
0.97x − 1.0
(0.04) (17.40)
1.06x − 30.1
(0.05) (25.01)
1.04x − 34.7
(0.03) (12.57)
Avg
difference,4
kg
(Range)
+16.8 (-2.7, 35.5)
Equal slopes
P-value5
0.06
+5.0 (-26.8, 24.6)
0.81
-2.3 (-34.1, 16.8)
0.01
-3.7 (-23.2, 15.0)
0.08
+4.6 (-15.9, 20.5)
<0.01
-2.1 (-32.7, 25.9)
<0.01
-12.5 (-39.1, 7.7)
<0.01
+15.5 (-38.6, 44.1)
0.47
+0.5 (-19.1, 20.9)
0.12
+9.2 (-2.7, 27.7)
0.03
+14.6 (-1.8, 27.7)
0.16
+11.5 (-2.3, 32.7)
0.86
+17.1 (+4.1, 31.4)
0.58
+18.5 (+1.4, 40.5)
0.14
+11.1 (0.5, 26.4)
0.21
+12.2 (+1.4, 35.5)
0.29
+3.1 (-13.6, 28.6)
0.35
+14.1 (-2.3, 35.5)
0.50
1Full-fed
weights (FFW) were measured while cattle had ad libitum intakes, limit fed weights (LFW) were measured after a 5-d period of restricting
intakes to 2% of BW. Individual cattle BW were plotted with each animal’s
FFW as the independent variable on the X axis and LFW as the dependent
variable on the Y axis, similar to Fig. 1.
Table 3. Relationships between 2 consecutive d of
weights taken after a limit-feeding period (LFW)1
Exp.
1
r2
0.973
2
0.971
3
0.936
4
0.939
5
0.986
6
0.977
7
0.913
8
0.927
9
0.984
10
0.994
11
0.991
12
0.987
13
0.992
14
0.974
15
0.974
16
0.983
17
0.985
18
0.991
Equation
(SEs2) (SEI3)
0.98x + 2.89
(0.03) (11.63)
0.98x + 6.55
(0.02) (7.91)
1.08x − 35.25
(0.05) (20.74)
1.02x − 6.09
(0.02) (8.46)
1.01x − 1.96
(0.01) (2.17)
0.99x − 0.88
(0.01) (3.77)
0.94x + 17.50
(0.02) (5.54)
0.93x + 22.45
(0.01) (3.94)
0.97x + 8.05
(0.02) (8.08)
1.03x − 10.77
(0.01) (5.00)
1.01x − 9.23
(0.02) (7.65)
0.97x + 5.82
(0.02) (7.27)
1.01x − 7.36
(0.02) (6.14)
1.01x + 2.14
(0.03) (10.95)
1.04x − 17.86
(0.03) (12.06)
0.99x + 1.55
(0.02) (8.87)
0.97x + 7.32
(0.02) (9.19)
1.00x − 5.27
(0.01) (5.02)
Avg difference,4
kg (Range)
8.4 (0.0, 45.0)
4.9 (-20.0, 15.5)
6.5 (-29.1, 8.2)
4.6 (-15.5, 15.5)
3.8 (-19.1, 16.4)
5.7 (-15.5, 23.6)
3.9 (-22.7, 14.6)
4.5 (-21.8, 15.5)
4.6 (–4.6, 11.8)
2.2 (–7.7, 5.0)
6.0 (-1.8, 14.1)
5.1 (-2.7, 13.2)
3.8 (–5.5, 11.4)
7.0 (-17.7, 10.5)
3.0 (–6.8, 9.1)
4.1 (–4.6, 12.3)
7.4 (–6.8, 14.1)
4.4 (–5.9, 11.4)
1Individual cattle BW were plotted with each animal’s d 1 limit-fed weight
(LFW) on the x axis and d 2 LFW on the y axis, similar to Fig. 2.
2Standard error of the slope.
3Standard error of the intercept.
4Absolute difference.
2Standard
error of the slope.
error of the intercept.
4Positive number indicates full weight greater than limit-fed weight; negative number indicates limit-fed weight greater than full weight.
5P > 0.10 indicates the slopes of FFW and LFW are not different from
each other.
3Standard
ADG was calculated using LFW for both beginning and
ending weights. In the other 13 experiments only LFW
were taken for beginning weights. For these experiments FFW ADG was calculated using LFW beginning
weights and FFW ending weights. The LFW ADG was
calculated using LFW beginning and ending weights.
For each group of cattle, data were plotted with each
animal’s FFW ADG as the independent variable on the x
axis and the LFW ADG as the dependent variable on the
y axis. All cattle are grouped together and plotted as an
example of how data were analyzed (Fig. 4). Differences
between FFW and LFW ADG were calculated, and an
average difference and range of differences are reported
for each trial (Table 5).
Out of the 15 experiments that were used to calculate
ADG, 13 had 2 or more treatments applied. An F test was
used to compare ADG on a FFW and LFW basis to determine if statistical differences between treatments would
5512
Watson et al.
Figure 2. Relationship between weights taken on 2 consecutive d after
cattle were limit fed for 6 d (LFW). Each point represents 1 animal on 1 of the
18 experiments. y = 0.99x + 4.27; r2 = 0.99.
Figure 3. Relationship between weights taken on 2 consecutive d while
cattle were fed ad libitum (FFW). Each point represents 1 animal on experiments 9 to 18. y = 1.00x – 0.94; r2 = 0.99.
be impacted by weighing procedure. For this analysis differences were considered significant at P ≤ 0.05 (Table 6).
cattle weights after 258 steers grazed cornstalk residue.
The average difference between FFW and LFW was
-12.5 kg, with FFW being 12.5 kg less than LFW (Table
2). The range of differences was -39.1 to +7.7 kg. Slope
was 0.88, with a SE of 0.03. Experiment 8 measured
cattle weights after 509 steers were on a forage-based
growing trial. The average difference between FFW and
LFW was +15.5 kg and ranged between -38.6 and +44.1
kg (Table 2). Slope was 0.94, with a SE of 0.02.
In most experiments, the overall average FFW was
numerically greater than LFW; however, in 4 of these experiments overall average FFW was numerically less than
LFW (Exp. 3, 4, 6, and 7; Table 2). In every experiment
there was at least 1 animal with a FFW numerically less
than its LFW. Within this data set there is not a consistent
relationship between FFW and LFW, which suggests that
FFW are highly variable and dependent on many environmental conditions. By controlling, or at least documenting, the environmental conditions at weighing, cattle
weights become more relevant and useful.
RESULTS AND DISCUSSION
Many factors can affect animal weights and should
be accounted for when measuring and reporting cattle
weights. A limit-feeding protocol attempts to reduce
variation in weights due to environmental conditions
such as time of day, gut fill due to ad libitum intake, and
how cattle are handled. Minimizing these factors is an
attempt to measure live weight of the animal and predict
empty body weight (EBW) of the animal. If this protocol is successful, accurate weights can be taken on large
numbers of cattle on growing diets without having to
slaughter the cattle.
Differences between FFW and LFW
Figure 1 shows data from all 18 experiments plotted to look at relationships between FFW and LFW.
Data from each experiment were plotted individually,
similar to Fig. 1, and are summarized in Table 2. Nine
experiments (Exp. 1, 2, 5, 9, 10, 11, 12, 13, 14) consisting of 593 animals measured cattle weights after grazing
smooth bromegrass pasture. Over all 9 experiments, the
average difference between FFW and LFW was +10.9
kg, with FFW being 10.9 kg greater than LFW (Table 2).
The range of differences was -26.8 to +40.0 kg. Slopes
of linear trend lines varied between 0.92 and 1.05, with
an average SE of 0.03. Seven experiments (Exp. 3, 4, 6,
15, 16, 17, 18) consisting of 571 animals measured cattle
weights after grazing Bermuda grass, fescue, or native
range. Over all 7 experiments, the average difference between FFW and LFW was +4.6 kg, with FFW being 4.6
kg greater than LFW (Table 2). The range of differences
was -34.1 to +35.0 kg. Slopes varied between 0.95 and
1.06, with an average SE of 0.05. Experiment 7 measured
Figure 4. Relationship between ADG calculated from weights taken using 2 different weighing procedures. Each point represents 1 animal on Exp.
1, 2, 8, or 9 to 18. Weights were taken while cattle were being fed ad libitum
(FFW) and after a limit-feeding period (LFW). Points below the isopleth represent animals with FFW ADG greater than LFW ADG. Points above the
isopleth represent animals with FFW ADG less than LFW ADG. y = 0.87x
– 0.079; r2 = 0.42.
5513
Variation in cattle weights
Table 4. Relationships between 2 consecutive d of
weights taken while cattle had ad libitum intakes (FFW)1
Exp.
9
r2
0.985
10
0.982
11
0.986
12
0.964
13
0.996
14
0.978
15
0.901
16
0.973
17
0.976
18
0.972
Equation
(SEs2) (SEI3)
1.02x − 8.32
(0.02) (8.09)
0.97x + 10.27
(0.02) (8.36)
0.97x + 14.77
(0.02) (6.19)
0.98x + 7.05
(0.03) (12.62)
1.00x − 2.82
(0.02) (10.43)
0.95x + 20.86
(0.02) (9.93)
0.97x + 11.73
(0.05) (23.54)
0.95x + 19.36
(0.03) (11.17)
1.00x − 0.23
(0.03) (12.00)
1.02x − 10.59
(0.02) (9.45)
Table 5. Relationships between ADG calculated from
LFW or FFW1
Avg difference,4 kg
(Range)
3.7 (-10.9, 9.1)
65
3.3 (–8.2, 12.3)
85
5.5 (-10.9, 5.5)
16
4.6 (-10.5, 18.2)
26
6.4 (-10.0, 15.9)
36
4.8 (-13.6, 12.3)
96
6.0 (–9.1, 5.9)
106
4.0 (–9.1, 10.9)
116
3.0 (-13.6, 6.8)
126
4.6 (–8.6, 34.1)
136
1Individual
cattle BW were plotted with each animal’s d 1 full-fed weight
(FFW) on the x axis and d 2 FFW on the y axis, similar to Fig. 3.
2Standard error of the slope.
3Standard error of the intercept.
4Absolute difference.
Exp.
146
156
166
176
One potential source of variation in LFW is due to
group feeding and cattle not all consuming exactly 2%
of BW in feed each day. This is overcome by having at
least 5 d of limit feeding and, more important, allowing
cattle at least 0.41 m (16 inches) of space at the bunk.
Research on bunk management has found no difference
in ADG and feed efficiency when cattle are allowed
0.15 to 0.60 m of bunk space, even when being limit fed
(Gunter et al., 1996; Zinn, 1989).
In all 18 experiments, LFW were an average of
weights taken on 2 consecutive d. In 10 experiments,
FFW were also an average of weights taken on 2 consecutive d. Figure 2 shows data plotted to look at relationships between LFW taken on consecutive days, and Fig.
3 shows data plotted to look at relationships between
FFW taken on consecutive days. Figures 2 and 3 include
data combined from all experiments; data from each
individual experiment are summarized in Tables 3 and
4. Two consecutive days of LFW were strongly associated within each experiment, with r2 ≥ 0.93 and ranging
from 0.93 to 0.99. The average difference between LFW
on different days was 5.2 kg and ranged from -29.1 to
+45.0 kg for individual animals (Table 3). For the 10
experiments conducted at Kansas State University the
2 consecutive d of FFW were also highly related, with
r2 ≥ 0.90 and ranging from 0.90 to 0.99. The average dif-
186
Full ADG,
LF ADG,
kg/d (Range) kg/d (Range)
0.67
0.70
(0.33, 1.06) (0.34, 1.18)
0.91
0.42
(0.31, 1.62) (-0.05, 0.95)
0.91
0.81
(0.50, 1.39) (0.46, 1.39)
1.01
0.99
(0.50, 1.52) (0.49, 1.42)
0.62
0.64
(0.14, 0.98) (0.34, 1.11)
0.90
0.91
(0.51, 1.19) (0.53, 1.23)
0.94
0.89
(0.58, 1.30) (0.52, 1.23)
0.87
0.79
(0.42, 1.22) (0.31, 1.16)
0.93
0.88
(0.67, 1.19) (0.57, 1.14)
0.92
0.84
(0.57, 1.22) (0.49, 1.15)
0.90
0.82
(0.66, 1.19) (0.54, 1.13)
1.22
1.10
(0.96, 1.51) (0.80, 1.42)
0.90
0.80,
(0.54, 1.32) (0.44, 1.18)
0.95
0.92
(0.49, 1.37) (0.38, 1.36)
0.92
0.86
(0.56, 1.18) (0.45, 1.16)
Avg difference,2
kg/d (Range)
-0.035
(-0.249, 0.190)
0.486
(0.033, 1.299)
0.099
(0.0, 0.267)
0.025
(-0.292, 0.145)
-0.019
(-0.281, 0.139)
-0.002
(-0.097, 0.106)
0.056
(-0.015, 0.171)
0.080
(-0.009, 0.151)
0.059
(-0.010, 0.165)
0.077
(0.019, 0.140)
0.083
(0.003, 0.178)
0.124
(0.003, 0.290)
0.108
(0.010, 0.313)
0.029
(-0.126, 0.269)
0.063
(-0.009, 0.157)
r2
0.77
0.40
0.94
0.89
0.78
0.95
0.95
0.96
0.94
0.97
0.95
0.75
0.91
0.90
0.95
Equation
(SEs3) (SEI4)
1.05x + 0.005
(0.04) (0.023)
0.51x − 0.041
(0.04) (0.036)
1.04x − 0.132
(0.04) (0.041)
0.92x + 0.059
(0.04) (0.041)
0.94x + 0.059
(0.09) (0.059)
1.03x − 0.027
(0.04) (0.036)
1.00x − 0.059
(0.04) (0.036)
1.05x − 0.118
(0.04) (0.032)
1.00x − 0.059
(0.04) (0.041)
1.03x − 0.100
(0.03) (0.027)
1.00x − 0.086
(0.04) (0.036)
1.00x − 0.122
(0.09) (0.122)
0.98x − 0.086
(0.05) (0.450)
1.10x − 0.122
(0.06) (0.054)
1.05x − 0.109
(0.03) (0.027)
1Full-fed weights (FFW) were measured while cattle had ad libitum intakes; limit-fed weights (LFW) were measured after a 5-d period of restricting
intakes to 2% of BW. Individual cattle BW were plotted with each animal’s
FFW ADG as the independent variable on the x axis and LFW ADG as the
dependent variable on the y axis, similar to Fig. 4.
2Positive number indicates full ADG greater than limit-fed ADG; negative
number indicates limit-fed ADG greater than full ADG.
3Standard error of the slope.
4Standard error of the intercept.
5Indicates ADG calculated from full- and limit-fed beginning and ending
weights.
6Indicates ADG calculated from limit-fed beginning weights and limit-fed
and full-fed ending weights.
ference between FFW on different days was 4.6 kg and
ranged from -13.6 to +34.1 (Table 4). For these same 10
experiments, the average difference in LFW on different
days averaged 5.2 kg and ranged from -17.7 to +14.1
(Table 3). Equal slopes analysis was used to compare the
slope of the line through the 2-d FFW data to the slope
of the line through the 2-d LFW data for each individual
experiment. The range in P-values was <0.01 to 0.86
(Table 2). In 8 of the experiments the slopes of the lines
were not different from each other (P > 0.20). Slopes of
the lines were different in 7 of the experiments (P < 0.10).
The remaining 3 experiments had intermediate P-values
5514
Watson et al.
Table 6. Statistical differences in ADG due to LFW or FFW weighing procedure1
1
2
3
Treatment
4
5
6
7
0.84b
0.70a
0.75a
0.65a
1.15c
1.08b
—
—
—
—
—
—
—
—
0.03
0.03
<0.01
<0.01
0.91a
0.86a
0.89a
0.87a
1.14b
1.11b
1.12b
1.12b
—
—
—
—
—
—
0.04
0.04
<0.01
<0.01
0.76a
LFW ADG
Exp. 9
FFW ADG
LFW ADG
Exp. 10
FFW ADG
LFW ADG
Exp. 11
FFW ADG
LFW ADG
Exp. 12
FFW ADG
LFW ADG
Exp. 13
FFW ADG
LFW ADG
Exp. 14
FFW ADG
LFW ADG
Exp. 15
FFW ADG
LFW ADG
Exp. 16
FFW ADG
LFW ADG
Exp. 17
FFW ADG
0.29a
0.90b
0.43b
0.90b
0.37ab
0.74a
0.29a
1.07c
0.53c
0.93b
0.49bc
1.06c
0.54c
0.04
0.03
<0.01
<0.01
0.81
0.79a
1.04
1.08b
0.88
0.87a
—
—
—
—
—
—
—
—
0.07
0.08
0.15
0.08
0.78a
0.71a
1.01b
0.96b
1.04b
0.99b
—
—
—
—
—
—
—
—
0.04
0.04
0.01
<0.01
0.68a
0.57a
0.97b
0.88b
0.97b
0.92b
—
—
—
—
—
—
—
—
0.02
0.02
<0.01
<0.01
0.80a
0.74a
1.02b
0.97b
0.97b
0.91b
—
—
—
—
—
—
—
—
0.04
0.04
0.02
0.01
0.75a
0.66a
1.01b
0.94b
1.01b
0.93b
—
—
—
—
—
—
—
—
0.04
0.04
0.01
<0.01
0.79a
0.69a
0.93b
0.87b
0.95b
0.90b
—
—
—
—
—
—
—
—
0.04
0.04
0.05
0.01
1.18
1.01
1.18
1.05
1.29
1.20
—
—
—
—
—
—
—
—
0.04
0.06
0.12
0.10
0.71a
0.60a
0.84b
0.72a
1.08c
0.99b
—
—
—
—
—
—
—
—
0.03
0.05
<0.01
<0.01
0.67a
LFW ADG
Exp. 18
FFW ADG
LFW ADG
0.59a
0.95b
0.90b
1.12c
1.15c
—
—
—
—
—
—
—
—
0.06
0.07
0.01
<0.01
0.81
0.73
1.00
0.96
—
—
—
—
—
—
—
—
—
—
0.04
0.04
<0.01
<0.01
Item
Exp. 1
FFW ADG
LFW ADG
Exp. 2
FFW ADG
LFW ADG
Exp. 8
FFW ADG
SEM
P-value
a–c Within
a row, means without a common superscript differ (P < 0.05).
weights (FFW) were measured while cattle had ad libitum intakes; limit-fed weights (LFW) were measured after a 5-d period of restricting intakes
to 2% of BW.
1Full-fed
of 0.12 to 0.16. In experiments where slopes were not
significantly different FFW could be adjusted to LFW.
However, this analysis demonstrates that unless cattle
are limit fed there is no clear way of determining if FFW
and LFW would be similar; under some conditions, FFW
and LFW may not be significantly different. Relative
differences between 2-d weights were consistent when
cattle were handled in a similar manner, regardless of
intake level. These experiments were all conducted in
pasture grazing systems where treatment would not be
expected to affect gut fill. Without EBW measurements
on these cattle it is unclear if LFW or FFW are more accurate or closer to actual body tissue weight.
Variation in cattle weights
Differences in ADG due to Weighing Procedure
In 15 experiments, beginning and ending weights
were used to calculate ADG. Figure 4 shows data for all
15 experiments combined; data from each experiment
were plotted individually for analysis, and results are
summarized in Table 5. Over all 15 experiments, FFW
ADG was 0.082 kg/d greater than LFW ADG and ranged
between -0.292 and +0.313 kg/d for individual animals.
Slopes ranged from 0.51 to 1.10, with an average SE
of 0.047. Differences in both beginning and ending
weights are compounded when calculating ADG, which
is reflected in the r2 of 0.40 to 0.97. Shorter treatment
periods also exaggerate these differences in ADG. By
spreading weights out over a longer period, variation
in weights due to weighing procedure can be overcome
(Stock et al., 1983). Experiment 8, with both FFW and
LFW ADG measured on 258 out of 509 steers on a forage-based growing diet, had the weakest relationship
between FFW ADG and LFW ADG at r2 = 0.40 (Table
5). For this experiment the trend line is not parallel to
the isopleth, suggesting that as gains increase, the error
in measuring that gain increases as well. This illustrates
that applying a 4% shrink uniformly across all cattle
will not correctly adjust full weights to a limit-fed basis. For these 18 experiments, shrink from FFW to LFW
ranged between –4.8% and +6.8%. Shrink measured on
16,590 cattle by Cernicchiaro et al. (2012) ranged between –5.8% and +14.8%.
Evaluating individual animals within this experiment illustrates that some measured gains are not biologically plausible. For example, 1 animal had a FFW
ADG of 1.62 kg/d. This animal was on a low-quality,
70% crop residue diet. This animal’s LFW ADG of
0.77 kg/d is likely more accurate. Another animal with
a large variation between weights had a FFW ADG of
1.34 and LFW ADG of 0.04 kg/d. These large changes
in measuring ADG could easily change conclusions
from this research and affect the outcome and profitability of producers using this information.
Weights taken on consecutive days while cattle were limit fed were highly correlated. Accurate
weights help identify small statistical differences between treatments. Just as important, accurate weights
help prevent type I statistical errors or concluding
there are differences between treatments when in fact
there are not. Table 6 shows statistical differences between treatments based on either FFW ADG or LFW
ADG for Exp. 1, 2, and 8 to 18. For Exp. 1, FFW data
show that ADG is greater for treatment 1 than treatment 2. Using LFW data, the conclusion is that ADG
is equal for the 2 treatments. In Exp. 2, 10 to 15, 17,
and 18 there are no changes in statistical differences
between treatments for LFW ADG compared to FFW
ADG. However, the different treatments respond dif-
5515
ferently to limit feeding, with FFW ADG being 0% to
15.4% greater than LFW ADG. Using FFW or LFW
to calculate ADG also changes the conclusions drawn
about treatments in Exp. 8, 9, and 16.
Components of Limit-Fed Weighing Procedure
Differences observed between FFW and LFW in this
study may be a function of both the limit-feeding phase
and using multiple-day weights to measure LFW. There
are many versions of limit feeding, but most recommend
taking multiple weights to overcome day-to-day variation and more accurately identify BW. There is a balance
needed between weighing on multiple days to obtain accurate weights and weighing too many days, resulting
in unnecessary stress on the cattle. Most research that
has been done on multiple-day weights agrees that 2 or
3 consecutive days of weights are adequate but not excessive (Koch et al., 1958; Stock et al., 1983; GutierrezOrnelas and Klopfenstein, 1991). Weighing more frequently can be used to decrease variation, which can
allow for fewer animals on an experiment (Lush et al.,
1928; Baker and Guilbert, 1942). With recent advances
in technology it is possible to measure full weights of
cattle multiple times per day, every day of a trial, without removing them from the pen. This method yields
multiple weights per day over an extended period of
time, which yields so many measurements that it is possible to overcome variation due to gut fill (Charmley et
al., 2006; Kolath et al., 2007).
The second component of the limit-feeding procedure limits intake of a constant ration to limit fill effects
and eliminate fill effects due to diet (Meyer et al., 1960).
Limit feeding does not constrain water intake but instead
allows cattle equal access to water at all times, as recommended by Whiteman et al. (1954). Shrink occurs most
rapidly during the first 3 to 4 h of feed and water restriction and generally slows down after the initial loss (Cole
et al., 1988; Coffey et al., 1997). For this limit-feeding
procedure, cattle are typically restricted from feed for
18 h before being weighed. Limit feeding does not limit
shrink from occurring but, instead, attempts to standardize shrink by exposing cattle to the same environmental
conditions, handling, and diet.
The 10 pasture experiments conducted at Kansas
State University demonstrate differences in weights due
to differences in intake. Cattle were handled in a similar
manner for FFW and LFW. Weights were taken at approximately 0800 h, and cattle were on forage-based diets and were not moved long distances. Variation within
the 2 d of FFW was very similar to variation within the 2
d of LFW. Conversely, cattle on the 8 experiments conducted at University of Nebraska were handled very differently for FFW and LFW. For some experiments, FFW
5516
Watson et al.
were measured after cattle were moved up to 1.6 km on
foot or shipped up to 322 km in semitrucks. For each
of these 8 experiments, cattle were then handled very
similarly on both days of LFW. The limit-fed weighing
procedure is comprised of 2 parts: handling the cattle in
the same way on 2 consecutive d of weights being taken
and restricting cattle intakes to 2% of BW. It appears
that handling the cattle in a similar manner when weighing is more important than limiting intakes to decrease
variance between weights. Limiting intakes is important
to measure weights that are close to EBW and to standardize shrink across all cattle.
In systems research, cattle are handled differently
during each phase of the system. Allowing for a limitfed period between phases where cattle are on a common diet is crucial for determining actual body tissue
gain for each phase. If cattle are weighed off cornstalks
and put directly on smooth bromegrass without LFW,
ADG will be misrepresented for each portion of the system. Accurate weights are more difficult to obtain with
forage-based growing diets than in feedlot settings with
high-concentrate diets (Koch et al., 1958). Larger variations in gut fill are seen with forage-based diets, and correctly weighing cattle off of growing experiments can be
much more challenging than weighing cattle after finishing experiments where HCW can be used (Meyer et
al., 1960). Typically, cattle are treated similarly before
beginning weights are taken, and it is ending weights
that can be problematic as treatments can often influence
gut fill. The only way to eliminate gut fill differences is
to slaughter cattle and measure EBW. By standardizing
final weights with the use of carcass weights, beginning
weights become the most important measurement and
the source of error in calculating ADG (Meyer et al.,
1960). Excessive trim is a concern when utilizing carcass weights but can be avoided with careful technique.
Conclusions
Accurate weights are crucial for research and are
equally important in industry settings. The financial
impact of inaccurate weights can be substantial in both
industry and research situations. A standard protocol
for weighing cattle is critical to compare cattle weights
across treatments, systems, locations, or research stations. Obtaining accurate weights can be challenging,
but every effort should be made to minimize variation
due to gut fill, technique error, and environmental conditions. By limit feeding cattle on a common diet and then
weighing early in the morning on 2 consecutive d, variation in gut fill and differences due to environment can
be minimized. The experiments included in this analysis
did not measure EBW of cattle, so no conclusion can be
drawn as to how correlated either LFW or FFW are to
EBW. It is clear that the relationship between LFW and
FFW is not consistent; thus, a standard weighing procedure is needed if actual cattle weights and gains are to be
compared across systems and locations.
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